This invention relates to the field of locksmithing and particularly to the area of masterkeys and coded reference key silhouettes.
During the normal locksmithing art, a locksmith is frequently called upon to produce a key for a particular lock without having the benefit of an original or reference key. A reference key is a key that has coded cuts which would unlock an appropriate lock and is used as a reference in making other keys on standard key-duplicating machines. If the original or a reference key is available, the locksmith can use the original or reference key to produce a duplicate key on a key cutting machine. Such machines are common in the trade, and several have been patented, (e.g. Juskevic's key cutting machine, U.S. Pat. No. 4,521,142 and Ferruzzi's Encipherment machine, U.S. Pat. No. 4,545, 709).
As shown in Juskevic, to reproduce a new key once a reference key silhouette is available, one merely clamps the reference key in a standard key-cutting device. The cutting wheel is then driven across the key-blank to reproduce the reference key silhouette on the new key. See Juskevic Column 3, lines 44-48 (guide means); column 4, lines 60-61 (key-blank); column 5, lines 1-17. These devices are in common usage throughout the United States.
The Mini-Mite Key Machine manufactured by Ilco Unican Corporation of Rocky Mount, North Carolina, manufactures a common key reproducing machine. As shown in the Mini-Mite instruction manual, a standard reference key is inserted in one vise while a key blank is inserted in a parallel vise. As the reference key moves across the stylus, the cutting wheel reproduces the reference key on the key blank. In order to use this Mini-mite key reproducing machine, one needs to have a reference key silhouette for the stylus to trace the silhouette and reproduce the new key.
When a reference or original key is not available, a locksmith must refer to a manufacturer's manual and must make coded cuts at specifically described angles and depths and in specific positions along the key-blank. (A key-blank is an uncut key from which coded cuts are made to form a duplicate key.) This reproduction by hand of these coded cuts necessitates a great deal of time and tedious effort. If a complete set of pre-cut coded reference keys were available, duplicate keys for any standard lock could be produced quickly on any key duplicating machine. However, the sheer number and storage bulk of these reference keys would make the standard process of having a reference key for every possible variation of reference cuts impractical.
Hundreds of possible reference keys would be needed to adequately stock a locksmith's shop. The current invention provides a unique method of making such reference keys available. An object of this invention is to provide a standard coded reference key silhouette in almost any instance when such reference key silhouette is needed to prepare a duplicate key for a lock. Another object of this invention is to provide a coded reference key with very few partial reference key silhouettes needed to be kept on hand, thus reducing the storage space required to duplicate standard keys.